Week 13 (Oct 28 - Nov 1)

Monday

Perks of one circuit in one CD
  • Length restriction due to PSA dimensions causes cuts in PMMA layer to be very close to each other
  • During fabrication, the small amounts of melted material in adjacent chambers could cause water to leak
  • The closeness of the chambers also makes for a troublesome fabrication

The PSA layers incorporation onto the PMMA middle layer was made as fabrication steps, during which some issues were encountered as mentioned above.
Yet another redesign will be made to incorporate one circuit in only one half of the disc.

Design possible with 2mm PMMA layer
  • Source chamber: 82°, (R=85, r=15), Area=5009.09495mm^2
  • Air chamber: 82°, (R=120, r=85), Area=5134.322327mm^2

Tuesday

Friday's design, one circuit in CD, works
  • The idea of having the circuit cover the entire CD was to have the center of mass at the rotation axis
  • Despite the perks mentioned on Monday, no water leakages were present
  • Acetate bottom layer was used, and no leakage around the substrate area were present
  • Flow reciprocation is possible

20241029_181430.jpg Complete device as per the design established on Friday, Week 12 (Oct 21 - Oct 25)

20241029_131922.jpg
20241029_131945.jpg Water in the source chamber (bottom right) a few seconds after removing from motor

20241029_132008.jpg Water in the source chamber (bottom right) three minutes after rotation

Design improvement
  • Change the membrane diameter to decrease the reciprocation time

Wednesday

The code was updated for the new design.
The rest of the day was dedicated to other academic activities.

Thursday

There was the intention to make some tests changing the membrane size to see the speed of the reciprocation.
During fabrication, there were some issues, but at the first try, there was no problem.

Fabrication issue
  • During rotation, the PSA near the fabrication defect starts to come apart. When pressure is applied, it eventually separates and water starts leaking.
Tweak design
  • It is possible to extend the air chamber to avoid further defects and water flow directly between the chambers (which happened during rotation)